The function of an intrusion alarm system is to detect an unauthorized entry into a defined secure area and to transmit this information to a specific control point. Specific advantageous characteristics of a security system are the ability to differentiate between human intruders and a potentially harmless intruder such as an animal; the ability to minimize the number of false alarms; the ability to prevent an override or bypass; and the ability to operate during adverse environmental conditions such as power failure, electrical storms, and prolonged temperature variations. The security system can be considered to consist of three basic subsystems: (1) intrusion sensor; (2) the control center; and (3) local and remote security systems.